Posted
by
samzenpus
on Monday January 30, 2012 @06:51PM
from the blast-from-the-past dept.

An anonymous reader writes "I used Lego's Digital Designer software to build a model of a Sinclair ZX81 — the computer that kicked me off on my interest in such matters way back in 1981. Until very recently, the software allowed you to upload your model, buy it and get a boxed set with all the pieces to build it (as well as instructions). The ZX81 model is as close to the shape of the original as I could make it, considering that Lego is quite a lo-resolution modelling tool. I even made it so that you can lift off the lid and see a representation of the PCB in side. I have also posted the model to Lego's Cuusoo site — a place where you can post ideas, and if they gain enough support they will be considered for production."

No kidding. Just downloaded and played with it for a bit, this program is awesome! I think it serves as a great introductory step towards 3D modeling for children, learning how to navigate a simple 3D space in the context of positioning pieces, and most kids are already very familiar with lego pieces, not so much with vertices and polygons.

Absolutely agree... when I first saw this I had assumed he was using mechanical logic or something to simulate the instruction set, but... a black box?!? Why in the world would anyone over the age of 6 care about this?

I second that also...now if it was emulating the inner workings as well (either via arduino or some other microcontroller or if it was truly 1337 and did working circuits with legos)...then it would be another story.

Exactly. The title is entirely misleading, it says, "Sinclair ZX81 Made Out of Lego." When it should say "Mediocre model representing ZX81 made out of lego."

This does nothing other than vaguely resemble a ZX81. If you are going to do a non-working model of a computer at least choose something interesting and challenging. Maybe a Cray-2 with the cooling waterfall in a 1-1 scale.

That's what you get when you cheap enough to use the CPU as a video generator (thus getting 10% or less free for general programming, unless you suspend the video).
I appreciate Sinclair being concerned with costs... Still, good thing Sinclair did not consider a morse-code keyboard.

That's what you get when you cheap enough to use the CPU as a video generator (thus getting 10% or less free for general programming, unless you suspend the video).

You're right- though actually it was more like 25%. However, that "being concerned with costs" is what made the ZX81 (and the ZX80) far more affordable than its competitors while still remaining a (just) usable mainstream hobbyist machine that brought computing to people in the UK who hadn't previously been able to afford it.

As you imply, one *did* have the option of "suspending the video" by entering "FAST" (full-speed) mode instead of the default "SLOW" (continuous display). This wasn't quite as bad as

Is this a joke. I actually checked to see if this was functional, and that just the case was lego, but no. Someone's made a pretend computer out of lego, and it's on the Slashdot front page. Unbelievable. I hope all you Slashdot subscription payers are happy with this; if I had one, I'd cancel it!

True. But even with a good keyboard it sort of sucked. Everything had to go through BASIC, if you wanted to do any sort of assembler you had to jump through hurdles to get past BASIC, and if you wanted to do any I/O you had to get BASIC to do it for you.

if you expanded it you had troubles with connections and needed to make sure everything was tight. Ie, you plugged stuff into the back as a daisy chain, bus-to-bus-to-bus.

Add just a little bit to it and replace the ROMs and it would have been a pretty goo

But even with a good keyboard it sort of sucked. Everything had to go through BASIC, if you wanted to do any sort of assembler you had to jump through hurdles to get past BASIC, and if you wanted to do any I/O you had to get BASIC to do it for you.

Not true; or actually almost not true. I wrote a two player battle tanks game for it in assembly because BASIC was way too slow. The only BASIC lines in were REM, which held the actual code, and the line that called that code. Additionaly, you didn't even have to

It'd be like me building a lego replica of my first computer, a Hewlett Packard 386 beige monstrosity. Who the hell would look at it and say anything other than "why did you build a big beige box out of lego?"

To be fair, the ZX81 was more important than some random beige box, as it was many people in the UK's first computer back in the early 80s, and has significance because of that. (But we already had that discussion four days ago [slashdot.org]- the thread is still live(!)- so probably not worth repeating it here!)

That said, I agree that there's really nothing to this. Someone constructed a passable scale model of a ZX81 out of Lego about as well as could be expected. (Given that the ZX81 is fairly small and flat to start

To be fair, the ZX81 was more important than some random beige box, as it was many people in the UK's first computer back in the early 80s, and has significance because of that. (But we already had that discussion four days ago [slashdot.org]- the thread is still live(!)- so probably not worth repeating it here!)

You're forgetting the Sinclair ZX80 (Z80 processor, 1K RAM expandable to 4K). If you made a lego model of that you'd need to include a model milk carton. That puppy would overheat if you didn't add extra cooling to the rubbish heatsink (in the form of a frozen milk carton).

I know that the ZX80 (the first computer under £100) came first, and was very successful by the standards of the time- according to Wikipedia, 100,000 of them were sold. However, it was the ZX81 that took things into another league altogether- apparently 1.5 million were sold!

A somewhat saccharin homage. Never-the-less eliciting fond memories and affirming that computing, like nostalgia, just ain't what it used to be. I'm glad there's room on/. for such occasional nonsense... HGH

The singularity hub might make a good replacement for slashdot. They have all the great nerdy articles but nothing of psychics on the moon or lego calculators that can't actually calculate. They have a commenting system but no users to comment. We have the commenting users, they have great content. Sucks to say this as I have been here since 97

I used to own one of these. I soldered it together out of a kit when I was 11, with some help from my dad. I accidentally left the soldering iron against part of the case though, so there was a neatly melted hole there.:-)

When we added the 16k RAM pack, we discovered that the power supply was stretched to its limit providing the current for all that. So he designed a new case out of wood and aluminum and also reverse-engineered the keyboard hookup and got a keyboard with actual moving keys from a local electronics parts shop. Unfortunately, there is now something wrong with how the tape jack is grounded, and it can't record on tape anymore.:-(

I still have it though, 30 years later. The first computer I ever owned. I even have the sheets I made up collecting machine instructions by addressing mode (since they were listed by number in the manual) to make it easier to write machine language programs for it. I wrote my own binary multiplier since the ZX-80 chip doesn't have a multiply instruction.

This lego thing is vaguely interesting. It's neat to see the familiar shape again.:-)

Yes, thats what all you whiney posters are coming on here and complaining because they thought it was a FUNCTIONAL zx81 made in lego!!! Bwahahahahaaaa!!!! I would like to sell you a lego reproduction of a Baby Zuckerburg.. nurture it for a few years and it will invent a facebook and become very rich to look after you in your old age....

What? I've been digitally modeling LEGO for a couple years now... it's called Minecraft. Oddly enough, there is now an actual Minecraft LEGO set in the works [slashgear.com]. At least the mapping should be fairly straightforward, but I wonder if it comes with Endermen that tear your lawn apart when you're not watching.